Casing cutter



N. T. MCCANN CASING GUTTER Aprl 27, 1937.

Filed Aug. 20, 1934 Patented Apr. 27, 1937 UNITED ySTATES PATENT oFFlcE CASING CUTTER Neal Thomas McCann, Westminster, Calif.

Application August 20, 1934, Serial No. 740,615

10 Claims.

This invention relates to a casing cutter and is disclosed in this application as an inside casing cutter.

An objectfof my invention is to provide a novel pressure producing means within the tool itself, and operatable on rotation of the tool, this pressurefproducing means forcing a fluid against a piston and thereby forcing the cutters outwardly to sever the pipe.

l0 Another object is to provide a novel means of stopping the functioning of the pressure producing means when cutters have been extended and the pipe has been severed.

Still another object is to vprovide a means for returning the fluid from behind the piston after the cut'has been made, so that the tool is returned to its original closed position and is ready for another cut.

An advantage of my invention is that the tool can be lowered togany point in the well and the pipe severed at that point, after which the tool can be raised or lowered to another position and another cut or cuts made.

Other objects, advantages and features of invention may appear from the accompanying drawing, the subjoined detailed description and the appended claims. Y

In the drawing:

.Figure 1 is a longitudinal, sectional view of my casingcutter. I

Figure 2 is a longitudinal, sectional view of the pump and the fluid conduit.

Figure is a vsectional View taken on line 3--3 of Figure 1.

`Figure l is a sectional View taken on line 4-4 of Figure'2. l

,Figure 5 isa longitudinal, sectional view on an enlarged scale vofthe pump plunger and valve.

Figure 6 is a fragmentary, longitudinal, sectional view vof my tool showing a modified type of cutter construction.

vReferring more particularly to the drawing, the numeral I .indicates a housing on the uppery end ofwhich is provided a box 2. Thevdrill pipe 3 screws into the box and the rtool' is operated by rotation of the drill pipe as will be further described.

v The box 2 extends into the top of the housing I and is held in position vby a .cap 4 which screws onto the-upper end -of the housing. The box 2 is splined into the housing I as shown at 5, but the box has` a limited longitudinal movement relative to the housing, the purpose of which will be further described. y

A power piston 6 is mounted in the bore 'I within the housing I, suitable packing 8 beingprovided on the piston 6 for the purpose of preventing leakage around this piston. A plurality of cutters 9 are pivotally mounted on the piston 6, and these cutters are adapted to be projected outwardly through slots Il) in the wall of the housing l.

A coil spring I I bears against the bottom of the piston 6 for the purpose of yieldably urging this piston upwardly, and to return the piston to its starting position shown in Figure 1.

A conduit I2 is attached to the box 2 by means of a pin I3 which extends through the box and through the conduit. A port I4 in the conduit permits fluid under pressure to flow into the box 1 above the piston 6 for the purpose of forcing the piston downwardly and the cutters 9 outwardly as will be further described. A coil spring I2 presses against the top of the conduit I2 to press the conduit downwardly if wear occurs around the pin I3.

The conduit I2 extends axially through the piston 6 and projects below the piston. Suitable packing I5 surrounds the conduit adjacent the upper end thereof to prevent leakage. The lower end of the conduit seats upon a nut I6, the nut being screwed into the upper end of a cylinder block I1.

The cylinder block is held stationary within the housing I. An axial bore I8 in the block I1 is aligned with the hollow nut I6. A pump plunger I9 is reciprocally mounted in the bore I8 for the purpose of forcing fluid under pressure upwardly in the conduit I2, and thence above the piston 6 for the purpose of forcing this piston downwardly. 'I'he cylinder block I1 is held stationary in the housing by the spring II which presses against the base of the block and also by suitable pins or the like (not shown) which extend thru the base flange of the block and into the housing.

A valve is seated above the plunger I9 for the purpose of holding the pressure produced within the conduit I2. The plunger I9 is slotted and fluid flowsv into the plunger through ports 2|. The ports 2| communicate with ducts 22 in the block I1. The space around the block I1 within the housing I is iilled with a liquid such as oil, and this liquid will therefore flow through the ducts 22 thence through the ports 2I and will be forced upwardly under pressure past the valve 20 as the plunger I9 reciprocates.

A cam sleeve 23 is journaled in the block I 1 below the plunger I9. The cam sleeve is provided with a cam slot 24. A pin 25 extends transversely through the plunger I9 and projects into the cam slot 24. It will be evident 5 that when the sleeve 23 is held stationary by the clutch plate (to be subsequently described) and the plunger I9 and the housing I are rotated then the plunger will be reciprocated so as to build up pressure.

10 The plunger I9 is non-rotatably held in the block II by means of the lugs 26 on the block which projects into longitudinal slots 21 in the plunger.

A clutch plate 28 engages the sleeve 23 in that l5 there is a tongue and groove coupling on the plate and sleeve. A spring 29 bears against the clutch plate 28 for the purpose of yieldably holding the clutch plate in engagement with the sleeve 23. A shaft 3U is splined into the clutch plate 28, and this shaft projects downwardly out of the bottom of the housing I. A plurality of springs 3| are attached to the lower end of the shaft 30, and these springs press against the inner wall of the casing or pipe for the purpose of holding the shaft 30 against rotation.

Thrust bearings 32 are provided on the shaft 30 for the purpose of reducing the friction between the shaft and housing I. The springs 3| bear against the casing with sufficient pressure to carry the entire load of the tool without slipping. Thus it will be evident that the shaft will be held stationary while the housing I is rotated by the drill pipe 3.

The clutch plate 28 and the sleeve 23 will both be held stationary relative to the housing I since the shaft 30 is attached to the plate and the shaft is held by the springs 3|. Therefore the plunger I9 will be reciprocated as the pin 25 traverses the cam slot 24. As the plunger reciprocates, uid under pressure; is forced upwardly in the conduit I2 and the plunger B will be forced downwardly.

The cutters 9 will be moved outwardly into engagement with the casing, and the rotation of the housing and the cutters will sever the casing. The downward movement of the plunger 6 compresses the spring II.

A pair of trip rods 33 extend vertically through the block I'I. When the plunger 6 has been lowered a distance sufficient to extend the cutters 9, the maximum amount, the plunger engages the trip rods and will force the plate 28 downwardly. The clutch connection between the plate 28 and the sleeve 23 is thus broken and the 55 sleeve is then free to rotate with the housing. The plate 2S is slidably mounted on the shaft 30 and when the plate disengages the sleeve 23, said sleeve is no longer held stationary and therefore can rotate with the housing. This will stop the action of the plunger, and no more uid is forced back of the plunger 6.

If it is desired to withdraw the cutters 9 and remove the tool or change its position, the drill pipe is pulled upwardly. The box 2 is thus 65 moved upwardly relative to the housing I because of the lost motion connection between the two. The conduit I2 attached to the box 2 is thus moved oi of its seat on the nut I6, and the fluid will drain back through the conduit into the space around and above the block I'I.

In Figure 6 I have illustrated a modied form of cutter mounting. A plurality of cutters 34 are pivotally mounted in the housing I and in slots 35 in the housing. The plunger 36 is formed with cam surfaces 3l which engage the inner face of the cutter 34 and swing these cutters outwardly around their pivots as the plunger is urged downwardly under pressure substantially as previously described.

In operation, my tool is lowered in the casing to the point desired. The springs 3| press tightly against the inner wall of the casing and hold the shaft 30 against rotation. The drill pipe to which the tool is attached is now rotated and the body of the tool rotates with the drill pipe. A clutch plate 28 on the top of the shaft 3D engages the cam sleeve 23, thus holding this cam sleeve stationary relative to the rotative movement of the body of the tool. The pin 25 on the pump plunger I9 operates in the cam slot 24, thus causing the plu-nger to reciprocate and forcing the fluid in the space around the cylinder block upwardly into the conduit I2. The fluid under pressure passes out of the port I4 above the piston 5. The pressure of the fluid forces the piston downwardly and the cutters 9 outwardly. The cutters engage the casing and the rotation of the body of the tool causes the cutters to sever the casing. When the cut is completed, the drill pipe is lifted, and the lost m0- tion connection between the blocks 2 and the housing permits the conduit I2 to be lifted off of its seat in the nut I6. The fluid above the piston then drains back thru the conduit into the space around the cylinder block and the spring II pushes the piston upwardly and retracts the cutters 9. When the piston 6 is pumped downwardly, as previously described, and adjacent the lower end of its movement, the trip rods 33 will be engaged and pushed downwardly. These rods which engage the plate 28, will force said plate downwardly thus disengaging the plate and the sleeve 23 which disengagement causes the pump to cease functioning because the drive to the sleeve 23 is broken, and therefore the pump will cease to reciprocate.

I-Iaving described my invention, I claim:

l. A casing cutter comprising a housing adapted and arranged to be mounted on pipe, a piston slidably mounted in the housing, a plurality of cutters in the housing, said cutters being engageable by the piston to project said cutters from the housing, a pumpy in the housing, means operatably engaging the pump to operate the same upon rotation of the housing, and means engageable by the piston, said last named means engaging the pump operating means, whereby the pump operating means is released when the piston reaches the bottom of its stroke.

2. A casing cutter comprising a housing adapted and arranged to be mounted on drill pipe, a. piston slidably mounted in the housing, a plurality of cutters in the housing, said cutters being engageable by the piston to project said cutters from the housing, a pump in the housing, means operatably engaging the pump to operate the same upon rotation of the housing, a conduit extending from the pump to the piston whereby pressure is exerted on the top of the piston, and means operatable on upward movement of the housing to open said conduit whereby iiuid is returned to the pump.

3. A casing cutter comprising a housing adapted to be attached to pipe, a plurality of cutters in the housing, said cutters being adapted and arranged to be projected outwardly from the housing, a pump means, drive means for the pump, said drive means being operatable as the housing is rotated, automatic means to release said drive means, and a conduit extending from the pump to the piston whereby fluid under pressure is conducted to the piston.

4. In a iiuid actuated casing cutter, fluid pressure producing means in the cutter, means operatable on rotation of the casing cutter to actuate said pressure producing means, and automatic means connected to the pressure producing means whereby the pressure producing means is stopped at the termination of the cutting stage of operation, a plurality of cutters, a piston, said cutters being attached to the piston, said fluid pressure producing means being adapted and arranged to exert pressure against the piston and to move the same whereby the cutters are extended.

5. A casing cutter comprising a housing adapted to be attached to pipe, plurality of cutters in the housing, said cutters being adapted to be projected outwardly from the housing, a piston in the housing, said piston engaging the cutters 'to extend them outwardly, a pump within the housing and rotatable therewith, a cam engageable by the pump whereby the pump is reciprocated, means to hold said cam stationary relative to the pump, said pump being adapted and arranged to exert pressure against the piston.

6. A casing cutter comprising a housing adapted to be attached tol pipe, a plurality of cutters in the housing, said cutters being adapted to be projected outwardly from the housing, a piston in the housing, said piston engaging the cutters to extend them outwardly, a pump within the housing and rotatable therewith, a cam engageable by the pump whereby the pump is reciprocated, means to hold said cam stationary relative to the pump, said pump being adapted and arranged toy exert pressure against the piston, an automatic means to release said cam holding means.

7. A casing cutter comprising a housing adapted to be attached tol pipe, a plurality of cutters in thehousing, said cutters being adapted to be projected outwardly from the housing, a piston in the housing, said piston engaging the cutters to extend them outwardly, a pump within the housing and rotatable therewith, a cam engageabie by the pump whereby the pump is reciprocated, means to hold said cam stationary relative to the pump, said pump being adapted and arranged to exert pressure against the piston, and a conduit extending from the pump tothe piston.

8. A casing cutter comprising a housing adapted to be attached to pipe, a plurality of cutters in the housing, said cutters being adapted to be projected outwardly from the housing, a piston in the housing, said piston engaging the cutters to extend them outwardly, a pump within the housing and rotatable therewith, a cam engageable by the pump whereby the pump is reciprocated, means to hold said cam stationary relative to the pump, said pump being adapted and arranged to exert pressure against the piston,

an automatic means to release said cam holding means, and a conduit extending from the pump to the piston.

9. A casing cutter comprising ai` housing adapted to be mounted on pipe, a plurality of cutters in the housing, a piston in the housing, said piston being adapted and arranged to extend the cutters from the housing, a pump within the housing and rotatable therewith, a cam sleeve, means coupling the cam sleeve and the pump together whereby the pump is reciprocated upon relative rotation of the cam sleeve and pump, a clutch plate engaging the cam sleeve, a stationary shaft, means on the shaft whereby said shaft is held stationary relative to the housing, said shaft being attached to said plate, a triprod engaging said plate, said triprod being engageable by the piston on downward movement of the piston whereby the clutch plate is released from the cam sleeve.

10. A casing cutter comprising a housing adapted to be mounted on pipe, a plurality of cutters in the housing, a piston in the housing, said-piston being adapted and arranged to extend the cutters from the housing, a pump within the housing and rotatable therewith, a cam sleeve, means coupling the cam sleeve and the pump together whereby the pump is reciprocated upon relative rotation of the cam sleeve and pump, a clutch plate engaging the cam sleeve, a stationary shaft, means on the shaft whereby said shaft is held stationary relative to the housing, said shaft being attached to said plate, a triprod engaging said plate, said trip rod being engageable by the piston on downward movement of the piston whereby the clutch plate is released from the cam sleeve, and a conduit extending from the pump to the piston whereby fluid under pressure is conducted to the piston.

NEAL THOMAS McCANN. 

